Electromagnetic holding brakes of this kind are used in medical devices in order to clamp and hold a movable sheet. The movable sheet is connected with a certain part of the medical device, the position of which can be changed. The braking force or holding force can be defined as the force the sheet can be pulled with, without any movements occurring between the electromagnet and the sheet. The braking force depends on the thickness of the sheet, the magnetic properties of the sheet, the power of the electromagnet and the surface friction between the electromagnet and the sheet.